In this paper, we capitalize on the localization framework of [1]} and present a partially-connected Receiving RIS (R-RIS) hardware architecture, comprising a few co-located single-RX-RF RIS subarrays, which can offer 3D localization in a computationally autonomous manner (i.e., a without the intervention of any BS or access point). Our intention is actually the development of a low-cost, low-complexity, energy-efficient, yet highly efficient, narrowband localization system, acting as the sole anchor for this computation task. In particular, the MS is assumed to transmit narrowband Sounding Reference Signals (SRSs), whose reception at the proposed partially-connected R-RIS, via its individual RX RF chains attached to distinct subarrays of meta-atoms, is used to obtain multiple independent angular measurements. These estimates are then mapped into the 3D Cartesian coordinates of the MS, which is assumed lying in the far-field of each R-RIS subarray.
